Improvement in sewing-machines



' J. N. TA-RBOX.

Sewing-Machine.

No. 213,146 Patented Ma r. 11,1879.

#1 .05 m m 6M UNITED STATES PATENT OFFIGE.

JOHN N. TARBOX, OF HAMILTON, ONTARIO, CANADA.

IMPROVEMENT IN SEWING-MACHINES.

Specification forming part of Letters Patent No. 213,146, dated March11, 1879; application filed July 12, 1878.

.To all whom it may concern:

Be it known that I, JOHN N. TARBOX, of Hamilton, Province of Ontario,Dominion of Canada, have invented or discovered certain new and usefulImprovements in Sewing-Machines; and I do hereby declare the followingto be a full, clear, concise, and exact description thereof, referencebeing had to the accompanying drawings, making a part of thisspecification, in which--like letters indicating like parts- Figure l isa perspective view of so much of 'a sewing-machine incorporating myinvention as is necessary to illustrate the same. Fig. 2 is a view inperspective of the same devices from the under side, and Figs. 3, 4, and

5 are detached views of some of the operative parts of the same morefully illustrative of their construction and operation.

The ordinary working-table of a sewing-machine is represented at A, andthe bracket and arm which carries the upper working parts arerepresented at B 13. Both are made hollow, and the ordinarydriving-shaft is arranged in the arm B in the usual or any known ordesired way, and with the band-wheel w and fiy-wheel w thereon. Acrank-arm, a, operated by the usual bent crank in this drivingshaft,plays in the hollow of the bracket B, and extending through the table Aby a suitablyproportioned crank-connection, a gives to the shaft a anoscillatory or rocking as distinguished from a rotary motion. This shaftis supported in suitable hangers or bearings 11 on the under side of thetable.

In proper position with reference to the needle-bar c, needle 0', andpresser-foot d, I arrange the roughened feed-plate c. This latter plateis attached to or made as a part of the feed-bar c and on the latter aretwo stops,

6 These two stops, Fig. 3, and the intermediate lower edge of thefeed-bar constitute three sides of a box or slot, and the fourth side isformed by a guide-rib, s, fixed in position on a lug, I), which projectsdown from the table. This guide-rib s has an incline, 8 The box or slotthus formed has a wrist, 8 preferably in the form of a friction-roller,playing therein, the same being attached to the end of a link, 8 whichlatter receives a reciprocating motion by a crank-connection, s, withthe oscillatory or rock shaft a A friction-roller on the outer end ofthe feed-bar 0 plays in a slot, 0 made for the purpose in the lug I), soas to allow the feedplate 0 to rise and fall, turning on such roller inthe slot 6 as a pivoting-point, and also so as to allow the entire feedto move longitudinally, and thereby move the cloth along as the stitchesare formed in succession. The parts thus designated are so proportionedand arranged that as the wrist 3 moves forward it shall ride up theincline s and thereby raise the feed-plate 0 into a sufficiently closeengagement with the cloth, and, continuing its stroke, shall comeagainst the forward stops, (or some interposed device, as presently tobe described,) and pushing. the stops along shall cause the fecd'toadvance the length of one stitch. On its return stroke it rides down theincline s. A spring, 6 causes the feed 0 to drop clear of the cloth, andthe wrist 8 engaging the other stop, moves thefeed backward the lengthof a stitch preparatory to taking a new bite on the cloth. It isimportant, however, in such machines to vary the length of the stitch.This I provide for by the use of a wedge, 'n, which is arranged to passthrough a slot in the lug b, so that its taper sides or point shall comebetween the wrist s and one of the stops 6", preferably the forward one,as shown. This wedge n, for convenience in adjustment, I attach to theend of a bar, a and pivot the opposite end of this bar to a lever, nfulcruined at of, Fig. 2, and to the opposite end of this lever I attach.a knob or handle, a, Fig. 1, which is on top of the table, inconvenient position to be manipulated by the operator. The stem of theknob n plays in a short slot, a Fig. 2, which gives the desired range ofmotion. By shifting the knob n the operator can cause the wedge a toadvance or recede inside the stop, and by the greater or less thicknessthus brought between the stop and the wrist s increase or decrease atpleasure the length of motion or throw of the feed, and as a consequencelengthen or shorten the stitch; but in I this part of my invention Iespecially include other equivalent mechanical means for effecting thesame result, such as an adjustable stop or a setscrew through thestop,or other known means suitable for lengthening or shortening thedistance between the stops, and thereby lengthening or shortening thestitch. The oscillating or rock shaft a also has affixed thereon ashuttle-carrier, t, which carries the shuttle i in the shuttle-head g,and causes it to move in the arc of a circle and in proper relationshipto the other operative parts. The shuttle is placed in the head 9laterally, or from the side shown in Fig. 2, and it is held therein by aspring, g. This spring has sufficient rigidity, or may be held by sidestops, so as to retain its place while the machine is running; but itmay also be sprung back and turned to one side on its point ofattachment, as a pivot, so as to permit of the easy insertion andremoval of the shuttle.

Another feature of my invention relates to a modification of theheart-motion, so called, by means of which I am enabled to run themachine with equal facility in either direction, or to reverse it at anyor almost any point without interfering with the continuity orregularity of the work. For this purpose, instead of making the groovein the heart-motion in the form of a V, as has heretofore been usual, Iflatten the middle part of the V, or make it horizontal, as shown inFigs. 4 and 5. The usual cranked disk It is made on the end of thedriving-shaft. The heart -motion block m is secured on the needle-bar cin the usual way, so that the crank-wrist (previously fitted with afriction-roller) shall play in the groove m m. The ends of this grooveare inclined, as at m, at about the angle usual in like known devicesbut such inclined grooves terminate in and are connected by a roove onstrai ht and horizontal, or nearly so. The result of this con- Istruction is that the needle will move slowly at the beginning of itsupstroke in forming the loop, and no great accuracy of adjustment willbe required.

In the V-motion the point or apex of the V, which determines thebeginning of the upward stroke, must be adjusted with such accuracy, inorder that the machine may run in either direction, that such resultcannot be attained by the ordinary user.

With the apex flattened, as in my improvement, any point at or near themiddle of the flattened or horizontal part m may determine the beginningof the upstroke, and within the limits of ordinary adjustment it is notmaterial which point of the horizontal groove on it be, since the resultin forming the loop will be the same whichever way the machine moves.Likewise, the reversal of the machine at any time prior to thecompletion of the stitch and the beginning of the forward stroke of thefeed will not interfere with the regular formation of stitches.

It is not essential, however, that the end grooves, m, be made withstraight sides, nor at any particular angle, since the angle may bevaried, or the top and bottom edges of such grooves may be made slightlycurved, the parallelism of adjacent sides being, however, substantiallypreserved. Also, the middle part, m may vary slightly from beingstraight without any substantial departure from the scope of myinvention, and without destroying the reversing capacity of the machine.

As a device for governing the slack of the thread I employ theperforated recessed bar and pin shown in Fig. 1. The pin 0 is attachedto the cover or front plate, 13, and the recessed bar 0 depends by abent arm from the upper projecting end of the needle-bar. Both areperforated horizontally, so that when the needle is at the lowest pointof its stroke the perforations or eyes in the pin and recessed bar willbe in line with each other. This facilitates materially the insertion ofthe thread.

I claim herein as my invention 1. A reciprocating arm, 8 having acrankconnection with an oscillatory or rock shaft, a in combination witha feed-bar having stops thereon, fixed or adjustable, and with aguiderib, 8, having an incline, s thereon, whereby the feed-arm willraise the feed-bar, and give it the proper reciprocating motion,substantially as set forth.

2. An adjustable wedge, a, or its described equivalent, in combinationwith feed-bar, stops, and reciprocating feed -link, to lengthen orshorten the free space through which the wrist of the feed-link movesbefore communicating motion to the feed-bar, substantially as set forth.

3. The combination, with the main drivingshaft of a sewing-machine andthe shuttleactuating and feeding devices connected there with, of theneedle-bar provided with a camblock, m having a groove, m horizontal ornearly so, which is interposed between and connects the inclined groovesm, and a crank carried by said drivingshaft, whereby the machine may beoperated to form stitches when the driving-shaft is rotated in eitherdirection, substantially as set forth.

In testimony whereof I have hereunto set my hand.

JOHN N. TARBOX. Witnesses:

J. J. MCCORMICK, CLAUDIUS L. PARKER.

